Douglas R. Heisterkamp Jing Peng Kernel Vector Approximation Files for Relevance Feedback Retrieval in Large Image Databases. 175-189 2005 26 Multimedia Tools Appl. 2 http://dx.doi.org/10.1007/s11042-005-0454-4 db/journals/mta/mta26.html#HeisterkampP05